The proposed study will develop an accurate segmental pulsatile pressure (SPP) analyzer and penile segmental cuff for detecting penile blood flow and pressure pulses. The goal is to construct two prototypes for studying and evaluating male impotence. Dr. Karacan's previous work on male impotence has shown that the proposed device could be used to detect and evaluate penile blood pulses. His work has shown that such a cuff must not cause physical deformity of penis during evaluation, and that the analyzer should be accurate and capable of maintaining cuff inflation pressure for 12 hours with no more than 5% droop. Early investigations were conducted with a cuff specially developed for detecting arterial blockage in limbs; the instrument (Pulse Volume Recorder, manufactured by Life Science, Inc.) could maintain cuff inflation pressure for only 30 minutes. Dr. Balkanli modified that instrument for the specific application and provided engineering consultation and two prototypes cited in this application. Clinical application will consist of evaluation erectile hemodynamics in normal and hypertensive males. Dr. Balkanli will license Texas Medical Electronics Co. to use U.S. Patent #4,279,155 (a bourdon tube transducer) for developing the two analyzer prototypes.